1. Field of the Invention
This invention relates generally to eye exercising devices and more particularly to portable eye exercising devices useful for correcting accommodation and convergence deficiencies of the human eye.
2. Prior Art
Binoculars-like eye training devices which force the user's eyes to accommodate for an actual or apparent change in the location of an image held by the device in the user's line of sight are known. For example U.S. Pat. No. 3,875,934 issued to Sadanaga discloses a device which reciprocates a pair of lenses along the viewer's line of sight and U.S. Pat. No. 2,213,467 issued to Greenspoon discloses a device in which a card is reciprocated toward and away from the viewer.
The prior art devices require that the user repetitively move the actual or apparent location of the image viewed toward and away from him along his line of vision so that the ocular muscles are exercised in the process. This tends to be very boring and users are inclined not to undertake the treatment which has been prescribed. This difficulty can be overcome by requiring that the treatment be undertaken in the doctor's office; however, this would result in considerable expense and inconvenience to the patient. Thus there is a need for an orthoptic training device which encourages continued adherence to the prescribed treatment regimen. This is particularly so in the case of devices for young children.